1. Field of the Invention
This application relates generally to building ventilation and specifically to roof ventilation.
2. Description of the Related Art
Energy efficiency is a serious consideration in new home design. New homes require ways to minimize energy requirements to maintain comfortable living spaces. One of the most common energy losses in a home is due to heat transfer through the attic. In warm climates, heat builds up in the attic from solar energy incident on the roof. In colder climates, moisture builds up in the attic, robbing the insulation of much of its R value. Early efforts at minimizing the effects of heat and/or moisture build-up focused on insulation between the living space and the attic. Gable vents and dormer type passive ventilation systems have been incorporated to ventilate the attic. U.S. Pat. No. 6,050,039 to O'Hagin describes one such camouflaged passive ventilation system. However, this passive ventilation system does not teach a camouflaged active ventilation system.
In other systems, active grid-powered ventilation systems using gable vents and powered dormer type vents have been used to increase the ventilation of the attic. These grid-powered active ventilation systems require increased operation and installation costs compared with passive systems. In the southwest, many homes have low pitch, hip roofs which have no gables, and dormers may destroy the aesthetics of a design if improperly located or too numerous. Therefore, these systems have proven to be inadequate.
What is needed is an improved ventilation system that will minimally detrimentally affect the appearance of a building design if used in adequate numbers to properly ventilate the attic, and is applicable to many roof configurations and with many types of roofing materials, while offering low operation and installation costs relative to other active ventilation systems. In addition, there is a need to provide a ventilation system automatically operable based on varying environmental conditions with minimal energy consumption.